RUTGERS UNIVERSITY
The State University of New Jersey

INSTITUTE OF MICROBIOLOGY

May 20, 1954 NEW BRUNSWICK, NEW JERSEY
CHARTER 7-1766

Dr. Joshua Lederberg

The University of Wisconsin
College of Agriculture
Department of Genetics
Madison 6, Wisconsin

Dear Josh:

Thanks for your letter and information. What I would like to
get from you is the streptomycin-resistant mutant of W-1 and 58-278,
which were isolated by replica plate technique, but never exposed to
streptomycin,

High degree of resistance is very convenient for me. I
would like to compare some of their biochemical properties before and
after exposure to streptomycin. I want to see if replica plating isolates
completely phenotypically expressed mutants or if the contact with
streptomycin induces some change in 100% in cells. I shall make my own
isolations too, but I am not quite settled yet, being only 3 days in New
Brunswick. Your cultures may save me some time.

This problem is interesting for me because I was able to
cause a complete, high degree streptomycin "adaptation" in 100% of non-

growing cells. It looks like a cytoplasmically inherited resistance.

I am looking forwarding to seeing you in New Brunswick, at
which time I shall explain this in more detail.

Yours sincerely,

wow

Waclaw Szybalski

WS:DP